烧结赤泥对磷酸镁水泥力学性能的影响及重金属固化效果研究

掺加烧结赤泥制备钙系磷酸镁水泥材料,通过力学性能测试、XRD和SEM分析研究了烧结赤泥掺量和反应条件对磷酸镁水泥微观形貌和力学性能的影响,并对重金属固化作用进行了初步探讨。结果表明:当烧结赤泥掺量为7%时,磷酸镁水泥的抗压强度达最大值43.27MPa、凝结时间13.4min、流动度127mm。此外,磷酸镁水泥能显著降低烧结赤泥中的重金属元素Pb^2+、Zn^2+、Cu^2+、Ni^2+的浸出浓度,浸出浓度远低于相应的鉴定标准,对其中所含的毒重金属元素均具有很好的固化效果。

Influence of red mud on mechanical property of magnesium phosphate cement and solidification effect of heavy metals

The magnesium phosphate cement(MPC)was prepared with red mud.The effects of different red mud content and reaction conditions on microstructure and mechanical properties of magnesium phosphate cement were studied by means of mechanical propertytest,X-ray diffraction(XRD)and scanning electron microscope(SEM),and the solidification effect of heavy metals was discussed preliminarily.It was showed that the maximum compressive strength of magnesium phosphate cement is 43.27 MPa,the setting time was 13.4 min and the flow rate is 127 mm when the dosage of red mud is 7%.The results showed that the MPC could efficiently reduce the leachate concentration of the heavy metals such as Pb^2+,Zn^2+,Cu^2+,Ni^2+and the concentrations of heavy metals in the leachate were all far lower than the corresponding assessment standard.It has a good solidification effect on the toxic heavy metal elements contained therein.